It physically hurts me when I hear of people using Quill Rain on their Elemental Hit characters. :(
Elemental damage is also Weapon damage, so you're hurting both your damage per hit and your Mana pool, massively.

In my opinion, Elemental Hit is a perfect skill for wands. Wands are ranged, have inferior base damage, but huge chance to crit, making flat damage from Elemental Hit very powerful. For all other weapons, Elemental Hit is inferior.